This invention relates to a flow control unit for accurately controlling the flow of fluid through a length of flexible tubing. More particularly, this invention relates to a combined clamp and flow control member which exerts a compressive force on a length of tubing over a wide area so as to prevent any permanent crimping of the tubing after the force is alleviated. The combined clamp and flow control member can completely compress the walls of the tubing so as to prevent fluid flow.
Clamping devices or fluid flow control units of the type concerned with in this invention are disclosed in U.S. Pat. Nos. 2,595,511 and 3,099,429. In these units, rollers are employed to exert an increasing or decreasing force upon flexible tubing so as to control the flow of fluid therethrough. The problem in employing clamps or flow regulating devices of these types is in the type of clamping action which a roller effects against a length of flexible tubing. When a roller contacts a length of tubing to compress it against a solid surface, the contact points on the roller compose a very small area at the circumference of the roller. The smaller the roller the more this is of a problem. In constructing a flow control unit to be used in conjunction with a parenteral solution unit large rollers are not practical. The prior art nowhere teaches a flow control device, and particularly of the disposable type, which is relatively small in construction yet can effect precise control of fluid through flexible tubing. Neither is there available a flow control unit which can serve as a combined clamp and flow control means which can be fabricated with a minimum number of parts and without costly molding techniques.
It is an advantage of the present invention to provide a combined clamp and flow control member which can precisely control the flow of fluid through flexible tubing without deforming the tubing for extensive periods of time after the compressive force is discontinued. Other advantages are a flow control unit which is disposable, employs a minimum number of parts, can be readily utilized with a single hand and can be fabricated without expensive molding procedures.